Revisiting this topic, I relocated back to the USA from China. I didn't want to bring back the fully assembled water bath, so I removed the essential components that would work on the USA power grid (110v versus 220v power), and started over. This also allowed me to improve some aspects of the system.
Here is what I didn't like about the original bath:
1) I used a cheap plastic storage tub from a local home supply store in Beijing. It had no insulation. On the positive side it was very cheap and very simple to work with. But insulation is very important with this device.
2) I felt spatially constrained. My jugs competed for floor space with the heater, pump, and temperature sensor. Also, I felt I wouldn't have room for E6, or even for a non-blix based C-41, with my dip-and-dunk setup. Wouldn't be a problem for daylight tank (patterson) processing, but for my large format I like doing a lights out dip and dunk, and that takes a lot of floor space.
3) When using the bath as a sous vide cooker, the bags of food would float into the heater. I worried the heater would melt open the bags or something else tragic.
I just finished rebuilding my system in the US. I used an Igloo Marine 70 qt cooler. The cooler has enough depth that I was able to place the heater, pump, and sensor at the bottom of the cooler, and create a rack above for tanks, using the full inside dimension of the cooler. I used the PID controller from China, which takes 110v with no problem. The temperature sensor similarly works fine (it doesn't depend on wall power). The immersion pump actually worked when I plugged it into 110v power, though it is only rated for 220. It also sounded like crap, so I don't think it survived the move very well. So I replaced it with a new, similar pump.
The heater and temperature sensors are mounted in through holes. I used 3" squares of plastic from Tap Plastic to mount the devices, and heavily sealed it all with clear silicone sealant. The pump was simply mounted in a corner on its side, with a plastic block holding it stable, while allowing it to be removed (in case it burns out, which they tend to do). The output blows directly onto the heater.
I like this setup. It is more roomy, it is insulated, and it has a drain at the bottom that my previous one didn't have.
Here are a couple of photos: